Paso Robles police responded to reports of a 'large physical altercation Friday.
It happened on the 1900 block of Riverside Ave.
When officers arrived they found a 29-year-old man on the ground with moderate head injuries as a result of being struck by a vehicle.
The suspect and suspect vehicle left the scene before officers arrived.
Police say a teen was contacted nearby the victim and found to have an unloaded 9mm handgun that was determined to be stolen from another state.
The teen was arrested for having a stolen firearm and booked at the San Luis Obispo County Juvenile Detentions Center.
The 29-year old man was conscious and transported to a local hospital for treatment.
Police say there is an ongoing investigation, and the Paso Robles Police Department is requesting anyone with any information to call the PRPD at (805) 237-6464 or persons wishing to remain anonymous are encouraged to call Crime Stoppers' 24-hour hotline at 805-549-STOP or by texting “SLOTIPS” plus your message” to CRIMES (274637).